Although the presence of significant quantities of connective tissue protein in the lung has been noted for several years, relatively little effort has been made to isolate, quantify and/or characterize these most important elements of the lung. Yet, all are agreed that these elements of connective tissue must be understood if one is to understand in full the processes of growth, development, aging and repair in the mammalian organism and one is to understand specifically, the physiology and chemical pathology of the several components of the lung. Specifically, this proposal is aimed at determining methods and procedures for the isolation and characterization of lung elastin from several species. In addition, we will attempt to elucidate the biosynthesis of lung elastin including formation and characterization of possible soluble precursor(s) as well as examining the biosynthesis of the lysine derived crosslinks which ultimately lead to fiber formation. BIBLIOGRAPHIC REFERENCES: Foster, J.A., D. Knaack, B. Faris, R. Moscaritolo, L. Salcedo, M. Skinner and C. Franzblau, "Development of a Specific Immunological Assay for Tropoelastin and its Application to Tissue Culture Studies" Biochim. Biophys. Acta (1976). Foster, J.A., L. Rubin, H. Kagan and C. Franzblau, "Molecular Model for Desmosine Crosslinked Peptides", Biopolymers 15:833 (1976).